Radiation Therapy and Cardiac Enzymes

Cardiac Biomarkers: Cardiac biomarkers are proteins made by the heart. When cardiac biomarkers are above normal levels, there may be damage to the heart. The relationship between cardiac biomarkers and radiation therapy has not been well studied. Learning more about this relationship may lead to better ways to check the heart during radiation therapy. How cardiac biomarkers can play a role in predicting future heart problems during radiation therapy will also be studied. Study Tests: If you agree to take part in this study, blood (about 1 teaspoon) will be drawn to measure certain cardiac biomarkers up to 2 days before radiation therapy, following the first treatment of radiation, within 2 days of finishing radiation therapy, and about 1 to 2 months after completion of radiation therapy. Once the blood testing is completed, any leftover blood samples will be destroyed. You will also have electrocardiograms (ECGs -- tests that measure the electrical activity of the heart) at the same time points as the blood draws. Length of Study: You will be off study after the last blood draw and ECG. This is an investigational study. Up to 30 patients will be enrolled in this study. All will be enrolled at M. D. Anderson.